Abrasive finishing article

ABSTRACT

An abrasive finishing article in which an axially projecting drive member secures the article to a support pad. The drive member is formed with a hollow threaded boss, disposed through a centrally defined opening in the article, and an outwardly extending member at the base of the boss disposed on the opposite side of the article to press the article against the support pad. The outwardly extending member can be formed with a plurality of tabs which are pressed into engagement with backing material of the article whereby to secure the drive member in intimate integral connection with the article. The support pad includes a core-socket member and an axial stud whereby the drive member boss may be threadably retained in female-male engagement with the stud and core member, respectively, the core member being formed with internal and external abutment surfaces for close fitting engagement with the top surface of the drive member and surfaces of the finishing article laterally thereof, respectively.

[451 June 6, 1972 [54] ABRASIVE FINISHING ARTICLE [72] Inventor: Joseph H. MacKay, Jr., Woodland Hills,

Calif.

[73] Assignee: Norton Company [22] Filed: Apr. 27, 1970 [21] Appl.No.: 32,295

[52] U.S.Cl ..5l/379 [51] 1nt.Cl. ..B24d 13/14, B24d 13/20 [58] Fieldoi'Search ..5l/358,377-379, 51/376; 29/243.52

[5 6] References Cited UNITED STATES PATENTS 3,136,100 6/1964 Robertson ..5l/378X 3,046,709 7/1962 Cook 260,336 6/1882 Thayer..... 1,811,037 6/1931 Albertson... 2,087,969 7/1937 Gookin .29/243.52X 2,902,799 9/1959 Beck ..51/379 3,500,592 3/1970 Harnst ..51/376 Primary Examiner-Donald G Kelly Alt0rney-Nils50n, Robbins, Wills & Berliner ABSTRACT An abrasive finishing article in which an axially projecting drive member secures the article to a support pad. The drive member is formed with a hollow threaded boss, disposed through a centrally defined opening in the article, and an outwardly extending member at the base of the boss disposed on the opposite side of the article to press the article against the support pad. The outwardly extending member can be formed with a plurality of tabs which are pressed into engagement with backing material of the article whereby to secure the drive member in intimate integral connection with the article. The support pad includes a core-socket member and an axial stud whereby the drive member boss may be threadably retained in female-male engagement with the stud and core member, respectively, the core member being formed with internal and external abutment surfaces for close fitting engagement with the top surface of the drive member and surfaces of the finishing article laterally thereof, respectively.

10 Claims, 12 Drawing Figures PATENTEDJUH 6 I972 8,667, 169

sum 10F 2 INVENTOR.

(/OSEPH H MACKFIY. JR BY MM, 0% 1% 5 33m PATENTEDJUN smz 3,667,169

sum 20F 2 IN VENTOR.

. E B/OSIEPH H. MACKAKl/R.

c/fuqgufvlnd,

'OWK J.

1 ABRASIVE FINISHING ARTICLE FIELD OF THE INVENTION BACKGROUND AND SUMMARY OF THE INVENTION A variety of designs have been developed for the drive member of rotatable finishing articles. Metal and plastic drive members have been provided which are secured by adhesive or by polymeric bonding to the backing material of the finishing article for ready attachment to a mating component on a support member. Such prior art drive members have presented various problems such as high manufacture cost, lack of reliability during use under high temperature, and stress difficulty of attachment to the support member, and the like. Examples of such prior art devices are shown in US. Pat. Nos. 3,270,467, 3,340,652, 3,166,877, 3,119,208 and 3,149,442.

In the present invention, a finishing article is provided incorporating a drive member which is highly reliable during use under all conventional temperatures and stresses and which is readily attachable to available support members. The drive member is of such simple construction as to enable the fabrication of driven abrasive finishing articles at very low cost. In accordance with this invention, the drive member comprises a hollow boss having an annular screw thread lip and which is formed with a member extending outwardly from the base thereof. The boss is inserted through an axial opening in the finishing article with the outwardly extending member disposed on the finishing side of the article, the drive member may be secured to the finishing article by any of a variety of methods. For example, the drive member may be press fit through a slightly smaller opening in the finishing article or it may be glued to the finishing article. Alternatively, the gripping ears may be punched through the outwardly extending member and bent over and pressed into biting engagement with the backing material of the finishing article to thereby mechanically and intimately secure the drive member to the finishing article. The finishing article can thus be provided with an integral drive member by simple mechanical operations allowing for rapid and economical manufacture of the article. I

The lip of the hollow boss is broken and curved inwardly to define an internal screw thread. In this aspect, the boss functions as a female component receiving the threaded axial stud of a support member. The support member is formed with an axially central retainer socket, about the stud, for mating engagement with the exterior surface of the boss. In this aspect the boss functions as a male component receivable within the socket. Accordingly, the drive member functions both as a female and a male component to obtain a structurally strong connection. In this regard, the vertical distance between the top surface of the boss and top surface portions of the finishing article laterally of the boss is controlled to a predetermined magnitude so as to accomplish close-fitting mating engagement of both surfaces with the central socket.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an abrasive finishing article constructed in accordance with the present invention, in disassembled position adjacent a support member;

FIG. 2 is a perspective view of a drive member and a portion of the finishing article prior to insertion into the finishing article;

FIG. 3 is a bottom plan view showing the drive member of FIG. 2 and a portion of the finishing article after the drive member is inserted and secured;

FIG. 4 is a cross-sectional view of the drive member, partial cross-section view of the finishing article, and cross-section view of a retainer socket therefor taken on line 44 of FIG. 3, in the direction of the arrows;

FIG. 5 is a perspective view of an alternative drive member and a portion of finishing article therefor prior to insertion into the finishing article;

FIG. 6 is a bottom plan view showing the drive member of FIG. 5 and a portion of the finishing article after the drive member is inserted therein;

FIG. 7 is a cross-sectional view of an alternative finishing article-drive member assembly;

FIG. 8 is a perspective view of another alternative abrasive finishing article constructed in accordance with the present invention;

FIG. 9 is a perspective view of the drive member utilized in the finishing article of FIG. 8 and a portion of the finishing article prior to insertion into the finishing article;

FIG. 10 is a plan view taken on line 10-10 of FIG. 8, in the direction of the arrows, showing the drive member of FIG. 9, and a portion of the finishing article after the drive member is inserted and secured;

FIG. 11 is a cross-sectional view of the drive member and partial cross-section view of the finishing article, taken on line 1 1-l1 of FIG. 10, in the direction of the arrows; and

FIG. 12 is a fragmented perspective view showing still another alternative embodiment of drive member.

DETAILED DESCRIPTION Referring to FIG. 1, there is illustrated an abrasive finishing article 10 in the form of a circular disc having backing material 12, such as fiber, cloth or the like, on one side and abrasive finishing material 14 on the opposite side. The finishing article 10 is formed with a drive member 16 axially central thereof and which is mechanically fixed by means of tabs or pierceears 17 pressed in intimate integral gripping connection with the material of the backing member 12 as will be described in more detail hereinafter. The drive member 16 is formed with a hollow boss 18 open at its outer end and having a lip 20 broken at 22 and curved inwardly to define an internal screw thread. A rotatable support member 24 is formed with a flexible flat-surface support pad 26 of rubberized material or the like.

The support member 24 is of a type which is readily available and is described in detail in my earlier application, Ser. No. 806,250, entitled Finishing Article and Support Member Therefor. The support member 24 receives a central connecting stud 28 whereby the support member is secured to a rotatable power tool. The connecting stud 28 extends through the support pad 26 and terminates in a threaded stud portion 30 which is formed to matingly engage the threaded lip 20 of the drive member 16. The bottom surface 32 of the threaded stud portion 30 may be substantially on a plane with the bottom surface of the support pad 26, however, the bottom surface of the support member 26 is formed with a central recessed portion 34 to accommodate the tabs 17.

Referring to FIG. 2, the construction of the drive member 16 and the manner of its connection to the finishing article 10 are more clearly illustrated. The finishing article 10 is formed with a central opening 36 slightly greater in diameter than the width of the hollow boss 18 and, in most instances, is a in'ch hole which has become somewhat of a standard in the industry. The drive member 16, as illustrated, is fonned with an annular flange 38 radiating from the base of the boss 18 for disposition against the abrasive material side of the finishing article 10. A plurality of tabs 17 are punched through the flange 38 and extend upright therefrom annularly about the boss 18. The drive member 16 preferably is constructed of a sheet metal material, such as cold rolled steel, and is formed integrally in one piece from a disc, as by stamping or the like, on progressive dies, so that the threaded boss 18 and tabs 17 are formed in a traditional stamping operation. The present design of the drive member 16 thus allows for very economical manufacture. The tabs 17 are formed so as to fold up from the flange about the periphery thereof and are sufficiently spaced from the boss 18 so as to define a clear area 40 as shown by the arrow (FIG. 4) for purposes hereinafter described. The tabs 17 are inserted through the material of the finishing article, as by puncturing the same, to project from the backing side 12 thereof.

As will now be apparent to those skilled in the art, the construction of the abrasive finishing article of the present invention provides a device which carries with it the drive means for securing the device to the power tool for rotation but at the same time provides an extremely economical finishing article that is totally discardable when the abrasive surface is worn down. Although such devices have been provided for relatively small diameter abrasive discs in the past, no such structure meeting all known standards has been available for resin-fiber type abrasive discs having large diameters, i.e. seven inches and above. Such large diameter discs have been employed with a central opening which fitted over the stud. A machine screw threaded nut having a flange thereon was then threaded onto the stud and tightened with a wrench. To remove the disc the nut had to be loosened with a wrench, removed, saved and reused with a new disc. With the discardable disc-drive unit of the present invention much more efficient operation of the device can be accomplished.

Referring now to FIGS. 3 and 4, the finishing article is illustrated after insertion of the boss 18 through the central opening 36 and the tabs 17 through the material of the article, and after the tabs 17 have been bent and pressed into biting engagement with the backing material 12. After the tabs 17- are disposed through the backing material 12, an annular member (not shown) is brought down onto the top surfaces 42 of the tabs 17 while the flange 38 is disposed against a supporting a'nvil (not shown). The-tabs 17 are thus bent over into pressing engagement with the backing material 12 so as to bite into the backing material 12, thereby pinching or gripping the material between the tabs 17 and the adjacent portions of the flange 38 as shown at 43. A strong mechanical connection is thus effected between the drive member 16 and the finishing article 10.

Referring further to FIG. 1 in conjunction with FIG. 4, the support member 24 is provided with an axially central socket member 31 which is formed with a hollow 33 through which the threaded stud portion 30 (shown in shadow) projects. The drive member boss 18 is received in the hollow 33 which is as deep as the effective height of the boss 18 so that the top surface 44 of the boss 18 is close-fit against the socket roof defining the hollow 33, while the top surface 45 of the aforenoted clear area" 40 is clamped against the bottom surface 46 of the socket member 31. By the foregoing simultaneous seating, the abrasive finishing article 10 when threaded into the support member 24 is directly and firmly secured and cannot move any further irrespective of forces which may be applied. The socket roof 35 is closely fit to the threaded stud portion 30, and forms a metal trap" against the drive member boss 18 so that there is no slippage between the abrasive finishing article 10 and the support member 24. The vertical distance between the top surfaces of the boss 18 and the top surface 47 of the backing member 12, as indicated by the arrow 48, is thuspredeterrnined with respect to the requirements of a particular support member 24 and is slightly shorter than the depth of the socket hollow 33. When the finishing article 10 is secured to the support pad 24, it is found that the article 10 is deflected centrally into the recessed portion 34 of the pad sufficiently so that a straight edge when placed across the abrasive surface 14 does not contact the flange 38.

Referring now to FIG. 5, an alternative finishing article construction is illustrated. As there shown, a drive member 50 is provided having a hexagonal shaped boss 52 formed integrally with an annular flange 54 extending outwardly'from its base. The boss 52 is formed hollow with a split lip in the manner of construction of the boss 18 of FIG. 2. The finishing article 56 to which the drive member 50 is to be attached is formed with a central opening 58 in the outline of a hexagon which is dimensioned so as to be slightly smaller than the outer dimension of the boss 52. Referring to FIG. 6, the drive member 50 is secured to the finishing article 56 by press-fitting the boss 52 into the opening 58 to thereby mechanically secure the drive member 50 to the finishing article 56 through frictional engagement therebetween. This manner'of securement is perfectly satisfactory in most situations of storage of the finishing article. When the finishing article is to be mounted on a support pad, such as the support pad 24 depicted at FIG. 1, it is attached in the same manner as attachment of the finishing article 10 of FIGS. l-4. lmportantly, once secured to the support pad in such manner, the drive member 50 very effectively and tightly wedges the finishing article 56 against the bottom surface of the support member socket 31 in the manner depicted in FIG. 4. The result is a very tenacious and effective securement of the finishing article to the pad.

Referring now to FIG. 7, there is illustrated another manner of securement of a drive member 60 to a finishing article 62. The finishing article 62 is provided with a central opening 64 which may be round and which is dimensioned so as to be substantially as wide as the width of the drive member boss 66. Prior to insertion of the drive member boss 66 into the opening 64, the top surface 65 of the drive member flange portion 66 is coated with a layer of adhesive 68 which bonds directly to the abrasive grit 69 of the finishing article 62. The adhesive need be only strong enough to secure the drive member 60 to the finishing article 62 for purposes of storage since, as indicated with respect to the structure of FIGS. 5 and 6, threading the finishing article onto a support pad of the type hereinbefore described results in a tenacious securement of the finishing article.

Referring now to FIG. 8, there is illustrated still another alternative construction of a drive member 70 for securement to a finishing article 72. The drive member 70 is mechanically fixed through an axially central opening 74 defined by the finishing article 72 by means of tabs 76 which are pressed into intimate integral gripping connection with the finishing article backing material 78.

Referring to FIG. 9, the construction of the drive member 70 and the manner of its connection to the finishing article 72 are more clearly illustrated. The drive member 70 is formed with a boss 80 and an annular flange 82 radiating from the base of the boss 80 for disposition against the abrasive material side 84 of the finishing article 72. The abrasive material 84 in the vicinity of the central opening 74 may be skived from the backing material 78 to provide a central cleared portion 86 to accommodate the flange 82. The plurality of tabs 76 are punched through the flange 82 and extend upright therefrom annularly about the boss 80. The tabs 76 are formed suffciently close to the boss 80 so that they can be inserted through the finishing article opening 74 along with the boss 80.

Referring now to FIGS. 10 and 11, the finishing article 72 is illustrated after insertion of the boss 80 and tabs 76 through the opening 74, and after the tabs 76 have been pressed into biting engagement with the backing material 78. After the boss 80 and tabs 76 are disposed through the opening 74, an annular member (not shown) is brought down onto the top surfaces 88 of the tabs 76 while the flange is disposed against a supporting anvil (not shown). The tabs 76 are thus bent over into pressing engagement with the backing material 78 so as to bite into the backing material 78, thereby pinching or gripping the material between the tabs 76 and the adjacent portions of the flange 82 as shown at 90. A strong mechanical connection is thus effected between the drive member 80 and the finishing article 72. The fully constructed finishing article 72 can now be threaded onto a support pad such as is illustrated in FIG. 1.

Referring to FIG. 12, still another alternative manner of forming the outwardly extending member and tabs is illustrated. As there shown, the flange 92 is relieved or cut out at spaced portions 94 and 96 and the resultant material is bent upwardly to provide tabs 98 and 100 respectively. Any number of such cutouts and tabs may be provided and they may take any desired geometric form.

As required, detailed illustrative embodiments of the invention have been disclosed. However, it is to be understood that these embodiments merely exemplify the invention which may take many different forms that are radically different from the specific illustrative embodiments disclosed. Therefore, specific structural and functional details are not to be interpreted as limiting, but merely as a basis for the claims which define the scope of the invention.

I claim:

1. An abrasive finishing article, comprising:

a backing member defining a central opening;

a drive member of unitary one-piece construction comprising a hollow boss disposed through said opening in projection from one side of said backing member, said boss having an annular lip defining a single screw thread opening for said boss, and an outwardly extending member at the base of said boss disposed on the opposite side of said backing member; and

finishing material on said opposite side of said backing material. 1

2. The invention according to claim 1 including means for mechanically securing said drive member in intimate integral connection with the material of said backing member.

3. An abrasive finishing article, comprising:

a backing member defining a central opening;

a drive member comprising a boss disposed through said opening in projection from one side of said backing member, and an outwardly extending member at the base of said boss disposed on the opposite side of said backing member;

means for securing said drive member to said article; and

finishing material on said opposite side of said backing material;

said securing means including portions of said outwardly extending member disposed on opposite sides of said backing member.

4. The invention according to claim 1 including said outwardly extending member having a plurality of tabs extending therefrom and pressed into engagement with the material of said backing member whereby to efiect said securing.

5. The invention according to claim 4 in which said outwardly extending member is a flange formed with a plurality of tabs extending through said backing member and bent over into biting engagement with the material of said backing member.

6. An abrasive finishing article, comprising:

a backing member defining a central opening;

a drive member comprising a boss disposed through said opening in projection from one side of said backing member, and an outwardly extending member at the base of said boss disposed on the opposite side of said backing member;

means for securing said drive member to said article; and

finishing material on said opposite side of said backing material;

said securing means including a plurality of tabs punched through said outwardly extending member to extend through to one side of said backing member and bent over into pressing engagement with the material of said backing member whereby to grip said material.

7. The invention according to claim 6 wherein said tabs fold up from said outwardly extending member and said tabs extend through openings in said backing member formed by said tabs.

8. The invention according to claim 1 in which said drive member comprises a hollow boss and including means for frictional engagement between the outer surface of said boss and said central opening.

9. An abrasive finishing article, comprising:

a backing member defining a central opening;

a drive member comprising a boss disposed through said opening in projection from one side of said backing member, and an outward] extending member at the base of said boss disposed on e opposite side of said backing member; means for securing said drive member to said article; and finishing material on said opposite side of said backing material; said drive member being of unitary one-piece construction formed with a hollow boss on said one side of said backing member having an annular lip defining a central single screw thread opening for said boss. 10. The invention according to claim 1 including a support member connectable with said finishing article, said support member connectable with said finishing article, said support member including a socket member defining a surface for abutment with the top of said drive member boss and an axial stud projecting from said abutment surface and threadable into said drive member boss, said socket member being formed with a shoulder portion spaced from said abutment surface to clamp said finishing article on portions thereof laterally of said drive member boss. 

1. An abrasive finishing article, comprising: a backing member defining a central opening; a drive member of unitary one-piece construction comprising a hollow boss disposed through said opening in projection from one side of said backing member, said boss having an annular lip defining a single screw thread opening for said boss, and an outwardly extending member at the base of said boss disposed on the opposite side of said backing member; and finishing material on said opposite side of said backing material.
 2. The invention according to claim 1 including means for mechanically securing said drive member in intimate integral connection with the material of said backing member.
 3. An abrasive finishing article, comprising: a backing member defining a central opening; a drive member comprising a boss disposed through said opening in projection from one side of said backing member, and an outwardly extending member at the base of said boss disposed on the opposite side of said backing member; means for securing said drive member to said article; and finishing material on said opposite side of said backing material; said securing means including portions of said outwardly extending member disposed on opposite sides of said baCking member.
 4. The invention according to claim 1 including said outwardly extending member having a plurality of tabs extending therefrom and pressed into engagement with the material of said backing member whereby to effect said securing.
 5. The invention according to claim 4 in which said outwardly extending member is a flange formed with a plurality of tabs extending through said backing member and bent over into biting engagement with the material of said backing member.
 6. An abrasive finishing article, comprising: a backing member defining a central opening; a drive member comprising a boss disposed through said opening in projection from one side of said backing member, and an outwardly extending member at the base of said boss disposed on the opposite side of said backing member; means for securing said drive member to said article; and finishing material on said opposite side of said backing material; said securing means including a plurality of tabs punched through said outwardly extending member to extend through to one side of said backing member and bent over into pressing engagement with the material of said backing member whereby to grip said material.
 7. The invention according to claim 6 wherein said tabs fold up from said outwardly extending member and said tabs extend through openings in said backing member formed by said tabs.
 8. The invention according to claim 1 in which said drive member comprises a hollow boss and including means for frictional engagement between the outer surface of said boss and said central opening.
 9. An abrasive finishing article, comprising: a backing member defining a central opening; a drive member comprising a boss disposed through said opening in projection from one side of said backing member, and an outwardly extending member at the base of said boss disposed on the opposite side of said backing member; means for securing said drive member to said article; and finishing material on said opposite side of said backing material; said drive member being of unitary one-piece construction formed with a hollow boss on said one side of said backing member having an annular lip defining a central single screw thread opening for said boss.
 10. The invention according to claim 1 including a support member connectable with said finishing article, said support member connectable with said finishing article, said support member including a socket member defining a surface for abutment with the top of said drive member boss and an axial stud projecting from said abutment surface and threadable into said drive member boss, said socket member being formed with a shoulder portion spaced from said abutment surface to clamp said finishing article on portions thereof laterally of said drive member boss. 